This invention relates generally to metal wood golf clubs, and more particularly to methods of casting head metal and resulting head configuration, with the objective of facilitating liquid metal flow to thin walls of the head.
At the present time, it has become desirable to provide larger metal wood heads containing the same or approximately the same amount of metal as prior smaller metal wood heads, due to need to facilitate ease and accuracy of ball striking, while at the same time complying with head weight limitations imposed by existent standards. Larger heads using the same amount of metal dictate need for shell wall regions of lesser thickness. This in turn increases the difficulty of successfully casting the head, since metal flow into thinner mold spaces is impeded, as for example by excessive cooling and from interruption or slowing before the metal can penetrate fully into all regions of the mold cavity. Also, reduced wall thickness tends to weaken the walls, leading to buckling or other failure modes during repeated use of the head in striking a golf ball, at high speed. There is need for means and methods of casting head metal which will alleviate these and other problems encountered in head shell configuration and casting.
Further, there is need for concentration of as much of the mass of the head as possible into the face of the club head and the portion of the head directly behind the face. This puts the mass of the head where it effectively contributes to the energy imparted to the ball, and also increases the strength of the head front wall.
In addition, very thin-walled, metal golf club heads present the problems of cracking and buckling of metal walls, and excessive front wall deflection, during ball impact. There is need to alter the manner in which shock waves are distributed within metal wood walls, as by providing a mechanism which guides, interrupts, spreads, or otherwise alters the shock waves which emanate from the face at impact, but while maintaining optimum wall thicknesses.